| 摘要 |
<p>The amplitude or frequency of a sinusoidal signal represented as sample values S1, S2, S3, S4 is estimated by computing a triplet of differences x1, x2, x3, where x1 is a difference between S2 and S1, x2 is a difference between S3 and S2, and x3 is a difference between S4 and S3. An indication of the estimate of the amplitude or frequency is computed as a ratio of algebraic functions of the differences x1, x2, x3. The amplitude is computed as the square root of a first ratio of algebraic functions, and the frequency is computed as an arc-cosine function of a second ratio of algebraic functions. Preferably the ratio is evaluated by a division operation computed as a polynomial approximation, and the square root function and the arc-cosine function are also computed as a polynomial approximation. Preferably ratios computed from a plurality of triplets are averaged together to give more accurate estimates. Preferably any ratio having a denominator value that has a magnitude less than a threshold value is excluded from the average of the ratios, so that the average will not be corrupted by any inaccurate result that could be obtained when dividing by a relatively small number. The method can be used for compensating a parasitic capacitance, or for monitoring the health of a plurality of signals in an electronic circuit. <IMAGE></p> |
